Patent GB-791582-A (GB)
Title: Improvements in or relating to contact welding apparatus
IPC: H01H11/04
Filed: 1956-05-15
Abstract: 791,582. Making electric contacts; welding by pressure; shearing. WESTERN ELECTRIC CO., Inc. May 15, 1956 [May 16, 1955], No. 15107/56. Classes 83 (2) and 83 (4). In an apparatus for welding a contact tape to another member means are provided to support the member, to feed the tape to overlap the member and to weld the tape to the member. A metal strip 27, Fig. 1, having a notched edge to form tangs 26 is intermittently fed by means 35 to advance groups of five tangs to a welding station where five sets of upper and lower electrodes 40, 41 simultaneously or in rapid succession weld to the five tangs the ends of five precious metal tapes 42 fed by a mechanism 43 which subsequently severs the welded ends from the tapes. A pair of rotary brushes 36, 37 scratch brush the tangs prior to welding and a support 39 holds the strip during welding. Strip feed means. A pair of rolls 46, Fig. 2, are intermittently rotated by means including a cam 47 on a shaft 48 driven by sprocket and chain from a motor, the shaft 48 being connected by sprocket and chain 52 to a main cam shaft 53. Strip cleaning means. Wire brushes 36, 37, Figs. 1 and 2, on opposite sides of the strip are mounted on motors 56 secured to a plate 57 oscillatable about a shaft 58. A spring 62 urges the plate to carry the brushes out of contact with the strip and a cam 63 on the shaft 53 cooperates with a lever 64 to intermittently swing the plate to move the brushes into contact with the strip. Strip support means. A flat block 39 having a horizontal slot 67, Figs. 9, 10, to support the strip has a recess 68 exposing five tangs and the slot is enlarged at 69 to allow the passage of the welded-on contacts. The block is secured to a slide 70 in a slideway 71 and a cam 39 on the shaft 53 acting through a lever 75 and a disengageable element 76 allows the slide to be lowered under the force of a spring 91 to position the strip below the tapes before welding and then raises the slide to engage the strip with the tapes. The element 76 may be turned through 90 degrees by a handle to disengage the lever 75 and to engage a similar lever associated with a further cam on the shaft 53 to raise the block 39 before welding and then permit its lowering. A pair of pins 159 on spring-pressed plungers 161 to engage holes in the strip are provided adjacent the holder and are actuated by levers 168 engaging cams 171 on the shaft 53. Welding electrodes. The lower electrodes 41, Fig. 10, are secured to the upper end of a slide 96 mounted in the slideway 71 and a cam 97 on the shaft 53 and a bell crank 98 act through a pin 103 adjustably mounted in a bore 104 in the slide to vertically reciprocate the slide. The pin 103 engages a cam-like adjusting member 105 which may be locked in a desired position in the slide 96. The upper electrodes 40 are secured to tubular arms 127 in sockets 128 in an insulating block 132. The block is held in a cradle 137 having trunnions 139 journalled in bearings 140 and the electrodes are biased by a spring 142 into the open position and a cam 144 on the shaft 53 co-operates with an arm 145 depending from the cradle to move the electrodes into the welding position. The tubes 127 are connected to coolant hoses 151 and coolant passages are provided in the lower electrodes 41. The five sets of electrodes are connected to a welding current source by a cam-actuated switch 156. Tape feed and cutting means. The feed means 43 comprises five feeding units 175, Fig. 1, mounted side by side on a carriage 176 supported in guides 177 on a frame 55. Each unit has a pair of guide rails 178, 179, Fig. 19, grooved to form a guideway for a tape 42 and supported in a recess 181 in a slide bar 182. The bar 182 is supported in a guideway 185 in a vertical plate 186 screwed to the carriage 176. The bar 182 and lower rail 179 extend beyond the upper rail 178 and the upper overhanging part of the bar 182 supports a feed jaw 193 pivoted at 194 and spring urged to engage a tape 42. The bar 182 is urged by spring 210 into a retracted position and is moved to advance a tape by a block 204 sliding in a slot 203 in an extension of the bar and pivoted to a rocker arm 206 which is rotated by a cam 215, on an auxiliary cam shaft 216, acting through a plunger 213. Five cams 215 are arranged on the shaft 216 which is connected through a universal and telescoping connection 218, Fig. 1, to a shaft 219 driven from the main shaft 53. The tape passes over a stationary jaw 223 on the plate 186 and under a clamp 224 and cutting jaw 225. The clamp and jaw are mounted in a guideway 226 and the jaw is connected to a link pivoted to a lever 228 and the clamp has a pin 229 engageable with the lever 228 to be moved upwardly and is engaged with a leaf spring 230 to be moved downwardly. The lever 228 is urged to rotate in one direction by a spring 232 and is rotated in the other direction by a rod 233 actuated by a lever 235 driven by a cam 241 on the shaft 216. The carriage 176 is advanced from its normal position after welding by a roller 250, Fig. 1, engaging a block 249 on the carriage and actuated from a cam 258 on the shaft 53. The jaw 193 is released from the tape during this carriage movement by a rod 260 which engages a depending arm 199 of the jaw 193 and a spring-urged pusher bar 263 actuated by a lever 269, slide 276 and lever 279 operated by a cam 283 on the shaft 216. Operation. The feed rollers 46 advance the strip intermittently to position sets of five tangs in the recess 68 of the guide 39 and during this advance the brushes 36, 37 are moved to contact, the strip. The slide bars 182 are advanced to feed the tapes 42 to overlap the tangs 26, the guide 39 being in its lower position during this feeding. After the tapes have advanced the guide 39 is raised to engage the tangs and tapes and the aligning pins 159 are raised to engage the holes in the strip. The clamps 224 are actuated to clamp the tapes and the electrodes are moved to effect welding of the tape ends to the tangs. The electrodes are moved away, the clamps 224 are withdrawn and the jaws 193 are moved away from the tapes. The carriage 176 is then advanced to position the cutting jaws 225 adjacent the welded tape end and the clamps and cutters are actuated to sever the ends of the tapes. The jaws 225 are retracted with the clamps 224 still operative and the carriage is withdrawn. During the return the jaws 193 are allowed to again grip the tapes and the clamps 224 are withdrawn, the pins 159 lowered and the apparatus is ready for another cycle.